Strap guide



May 1, 1962 H. R. MERTENS STRAP GUIDE 2 Sheets-Sheet 1 Filed July 26, 1960 l 20 f0 Z6 25 7 5 m 3% m al v Hww United States Patent 1 3,031,816 STRAP GUIDE Howard R. Martens, Worth, lll., assignor to Acme Steel Company, Chicago, 111., a corporation of Illinois Filed July 26, 1960, Ser. No. 45,367 13 Claims. (Cl. 53-198) This invention relates to the art of strapping and particularly to improved strap guiding means for pallet strapping.

It is quite common to palletize a load by placing the load on a supporting pallet and encircling both the pallet and the load with metal binding straps in order to secure the load to the pallet so that the palletized load can be subsequently handled as a unitized package during storage and shipment.

Many times the supporting pallets are provided with notches or other type openings at their margins for the purpose of providing passageways through which the binding straps can be guided as they are directed beneath the load while encircling them about the load. Because these notches and openings are usually located in or adjacent to side or end runners of the pallets, they do not provide support for the straps between the runners so that additional guide means must be positioned between the runners for proper guiding of the straps between the runners.

One form of strap guide used between the runners consists of a trough into which the straps are fed, the trough bridging and guiding each strap from a notch or opening on one side of the pallet to an aligned notch or opening on the other side of the pallet. The disadvantage of this trough guide system is that the notches or openings of the pallet must be aligned with the trough so that proper strap guiding can occur.

It is an important object of this invention to provide an improved guide for location between the runners of a pallet of a type having strap guiding notches or openings in the runners or adjacent thereto, which guide does not require critical alignment with the pallet strap guide notches or openings and still provides proper guiding of the strap between the runners.

It is another object of the invention to provide such a guide in the form of a fiat plate which is positioned to bridge between the runners of a pallet for the full length of the pallet and thereby provide a horizontal guiding surface bridging between all of the strap guide notches or openings of the pallet regardless of their spacing from each other.

It is still another important object of the invention to provide an improved strap guide which has particular advantage for strapping a pallet of a type having spaced apart support runners mounted below a load supporting platform which is provided with one or more open bot tom strap openings extending transversely between the support runners, the strap guide being used as a temporary bottom wall for each of the open bottom strap openings during feeding of the strap beneath the pallet.

It is still another object of the invention to provide a horizontal guide plate of the type mentioned which is spring loaded upwardly to normally extend above the level of the bottom surface of the platform of the pallet whereby the pallet is used to depress the plate against spring pressure and thereby insure pressure of the plate against the lower surface of the platform so as to limit the strap paths to those in alignment with the strap guide notches or openings.

It is a further object of the invention as a result of the spring loading of the plate to provide the plate as a brake means, especially on an inclined conveyor, which automatically stops and maintains the pallet and its load in strapping position above the plate until forcefully transported ofi of the plate to another station.

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It is another object of the invention to provide camming means on the plate against which a pallet contacts and causes progressive depression of the plate for allowing the pallet to be conveniently positioned above the plate.

It is still another object of the invention to provide such a guide plate which lends itself to use on a continuous conveyor type assembly line operation.

It is another object of the invention to provide a floating type spring loading of the guide plate so that it dis plays a self-centering feature by distributing its contact area evenly against the bottom surface of the pallet platform.

A further object of the invention is to provide a strap guide plate which is segmented with the segments overlapping each other and movable over each other in a telescoping manner so that the strap guide plate is adjustable in width.

Still another object is to provide such a strap guide plate adjustable in width having spring biased means between the segnents and camming surfaces against which a pallet being transported to the strapping station can cam in order to automatically adjust the width of the strap guide plate to the width of the space between the runners of the pallet to insure strap guiding for the full distance between pallet runners.

It is still another object of the invention to provide such a spring biased adjustable width strap guide plate wherein the spring bias force provides braking action to the moving pallet against its runners.

Other objects and advantages of the invention should become apparent by referring to the accompanying drawings in which FIG. 1 shows a perspective view of a typical conveyor type strapping line embodying the invention;

FIG. 2 shows a perspective view of a pallet with which this invention can be used to advantage;

FIG. 3 shows a longitudinal sectional view of a portion of the conveyor shown in FIG. 1 and particularly shows a side elevation of the strap guide plate of this invention and its mountings. In this view the strap guide plate is shown in its normal position without a pallet in position over it;

FIG. 4 shows a top plan view of a portion of FIG. 3;

FIG. 5 shows a sectional view similar to FiG. 3 except that a loaded pallet is also shown positioned on the depressed strap guide plate of this invention;

FIG. 6 shows a modified form of the guide plate of this invention having spring loaded side guides, and

FIG. 7 is a sectional view along the line 7-7 of line 6.

A pallet 1 of a type which can be strapped advantageously by the use of the invention is shown in FIG. 2 and consists of three parallel equally spaced runners 2, 3 and 4 connected together by means of a platform consisting of parallel spaced boards 5 extending perpendicular to the runners 2, 3 and 4. These boards 5 are nailed or otherwise suitably fastened to the runners. The spacing of the parallel boards 5 is deliberately such that the spaces 6 between them are wider than the width of strap used for binding the load to be supported on the pallet so that straps can be guided through these spaces 6 when the strapping operation is performed. These spaces 6, in effect, are strap guide notches or openings above the runners 2, 3 and 4 and are open bottom spaces between the runners.

As shown in FIG. 1, a typical conveyor 7 on which loads can be palletized conveniently on pallet 1 consists of three parallel roller courses 8, 9 and it} on which the three runners 2, 3 and 4 of each pallet 1 can be positioned. For convenience, the conveyor 7 can be divided into three main portions, a receiving station 11, a

ping station 13. At the receiving station 111, a pallet l is provided with a load 14 supported thereon and the load 14 may consist of a single large object or a plurality objects stacked preferably into a rectangular cubicle length and width dimensions corresponding to those of the supporting pallet 1. The loaded pallet l is then transported down the incline of the conveyor 7 to the transverse strapping station 12 where straps l and 16 are encircled around the load 14 with the leading ends of the straps overlapping the supply ends of the straps and interlocking joints formed between the strap ends to provide closed loops around the load 14. The straps l5 and 16 are preferably fed to the load 14 from guide tubes 17 and 18 which guide the strap from coils of the strapping material (not shown) positioned adjacent to theconveyor 7. The interlocking joint formed between the overlapping strap ends is effected by means of a conventional strapping tool 19 suspended in the vicinity of the transverse strapping station 12 above the load 14. This strapping tool 19 can be a single combination tool of conventional type which is used to both tension the strap, form the joint and sever the strap loop from the supply end of the strap, or else conventional individual tools can be used for each of these functions. The type of tool used forms no part of the invention and there are many tools known in the art for this purpose.

At the transverse strapping station 12 and below the level of the boards 5 of the pallet l are two strap guide ing means to halt and maintain the palletized load at 7 this strapping station and also act as a glide for the transverse straps 15 and 16 as they are encircled about the palletized load.

After the transverse straps 15 and 16 are encircled about the palletized load and properly joined together as encircling loops, the strap load and pallet are pushed forward to the longitudinal strapping station 13 where longitudinal straps 21, 22 and 2 3 are applied around the load and the pallet in the direction normal to the direction of the transverse straps 15 and 16. These straps 21, 22 and 23 are anchored at their leading ends by strap grippers 24, 25 and 26 which are positioned between the roller courses 8, 9 and 10. Before the palletized load is presented to the longitudinal strapping station 13, the straps 21, 22 and 23 extend vertically from tubular strap guides 27, 28 and 23 which guide these straps from supply coils (not shown) adjacent to the conveyor 7. As the palletized load contacts these vertically positioned straps, and continues to move forward, the straps are bulged into wrapping engagement around three sides of the palletized load as shown in FIG. 1. Next, the strap grippers 24, 25 and 26 are released from the strap ends which are then brought around into overlapping engagement with the portions of the straps leading from the guide tubes 27, 28 and 29. A combination strapping tool 30 is then used to tension the straps, provide interlocking joints between the strap ends and thereafter sever the then existing strap loops from the supply portions of the straps. Just as in the case of the strapping tool 19, separate tools can be used to perform separate functions of the combination strapping tool 30. When the straps 21, 22. and 23 are finally tensioned and joined as encircling loops about the palletized load, the job is complete and the result is a unitized load strapped securely to the pallet whereby it is then ready for subsequent handling and shipment.

As shown in FIGS. 3 and 4, each strap guide plate 20 is of rectangular shape in plan view'and provided at its rear end with a downwardly extending cam portion 3i and a downwardly extending cam portion 32 at its forward end. The purpose of these cam portions 31 and 32 is to provide cam means against which the leading board 5 of the pallet 1 can be used to cam the plate 20 down- 4 wardly. The cam plate 20 preferably extends slightly above the board surfaces 5a of these boards 5;

Secured adjacentto the ends of the guide plate 23 are downwardly extending flanged tubes 33 and 34 which telescope around smaller tubes 35 and 36 which are secured to the door 37 supporting the conveyor by means of screws 33. Within each set of tubes 33, 35 and 34, 36 are helical compression springs 39 and 4%}, respectively. The upper ends of both springs 39 and 43 react against the lower surface of the guide plate 2% while the lower ends of both of these springs 39 and it) react against the floor 37. These springs urge the guide plate 2%? vertically upward. The tube 35 is provided with a projecting pin 41 which projects into a slot 22 in the tube 33 and the lower end of the slot limits the upward movement of the tube 33 by contact with the pin 41. The tube 36 is provided with a projecting pin 43 which projects into a slot as in the tube 34- andthe lower end of the slot limits the upward movement of the tube 34 by contact with the pin 43. This limitation of the movement of both of the tubes 33 and 34' naturally limits the upward position of the guide plate 20.

As a pallet 1 with a load 14 thereon cams against the camming portion 31 of the guide plate 2%) and moves over the guide plate 24} while depressing it, it ends up in a position centrally of the guide plate as shown in FIG. 5 with the guide plate 20 resting upwardly against the bottom surfaces 5a of the boards 5 of the pallet l. in this position, the plate 20 bridges the open bottom spaces 6 between the boards 5 and the spaces 6 are then enclosed guides for the straps l5 and 16 when they are passed therethrough.

It should be noted that the transverse straps 15 and 16, in the situation shown, are encircled only about the load 14 without securing the pallet 1 to the load 14. This does not mean that the transverse straps l5 and 16 cannot be used to secure the pallet to the load 14. Certainly a pallet can be designed whereby the pallet can be secured to the load 14 by means of the transverse straps 15 and 16. A simple way to do this is to place another layer of boards like 5 above the boards shown in FIG. 2 in a direction normal to those shown. This new top layer of boards would then be the ones around which the straps would be applied to secure the pallet to the load 14.

It is likely that on some installations the pallets will vary in width and their runner or leg spacing will not necessarily be the same for every pallet. In such a situation, it is desirable to design the guide plate and its supports as shown in FIGS. 6 and 7 with adjustable spring loaded side guides so that complete bridging is provided between the pallet runners. In FIGS. 6' and 7 a guide plate 45 similar ":1 function to guide plate 29 is provided. This gut: plate 45 has provided at its lower surface two tub: 33 and 34. Each is mounted over tubes 35 and 36 in the same manner as those shown in FIGS. 3, 4 and 5. Both are provided with compression springs 39 and 40, slots 42 and 44 and pins 4-1 and 43 for the same identical purposes. The guide plate 45, however, is provided with two side guide plates 46 and 47. The side guide plate 46 is secured to two spaced pins 48 each having an enlarged head 49 guided in one of two grooves 50 in the guide plate 45. The lower end of each pin 48 extends downwardly beneath the level of the side guide plate 46 and contacts the outer end of one of two compression springs 51 which is contained in a U-shaped sleeve 52 secured at its inner end to one of the tubes 33 or 34. Ordinarily, the springs 51 urge the pins 48 outwardly where they are stopped by the outer ends of the grooves 50. Upon pressure inwardly against the edge of the side guide plate 46, the pins as are moved along the guides 50 and they compress the springs 51.

In a similar manner, the side guide plate 47 is provided with two pins 53 each of which extends through one of two slots 54 in the guide plate 45. The lower end of each of the pins 53 extends downwardly below the level of the guide plate 45 and reacts against the outer end of one of two springs 55 which are housed in U-shaped sleeves 56 secured at their inner ends to the tubes 33 and 34. The inner ends of the springs 55 react against these tubes 33 and 34 in such a manner as to urge the pins 53 outwardly, being limited in their outward movement by the outer ends of the slots 54 and, thus, limiting the outward lateral movement of the side guide plate 47.

As a pallet 1 is moved on the conveyor 7 toward the guide plate 45 in the direction of the arrow 57 in PEG. 6, the bottom surface of the leading board of the pallet 1 reacts against the leading portion 58 of the guide plate 45 which portion 58 is bent downwardly to act as a camming surface. Similarly, the forward portion 59 of the guide plate 45 is bent down to provide a camrning surface for a pallet moving in a direction opposite to that of the arrow 57. As the pallet 1 continues in the direction of the arrow 57 it depresses the guide plate 45 and contacts the margins of the side guide plates 46 and 47 along the inner walls of the runners of the pallet 1. The side guide plates 46 and 47 are rounded off at their corners 46a and 47a to provide camming surfaces for the purpose of properly deflecting the side guide plates 46 and 47 toward each other against the pressure of the springs 51 and 55. When the pallet 1 is finally centrally in place over the guide plate 45 the margins of the side guide plates 46 and 47 are urged by the springs 51 and 55 against the pallet runners so that complete bridging for guiding of the strap between the runners is accomplished. It should be observed that the side guide plate 47 rests on top of the guide plate 45 while the side guide plate 46 is below it. The reason for this is to allow feeding of the straps 15 and 16 in the direction of the arrow 60 without snagging at the edges of the overlaps. If it is intended that strap feed should be in the opposite direction, the overlapping would preferably be opposite also and this can be accomplished by rotating the entire device 180 degrees in a horizontal plane.

In order to accommodate the proper overlapping of the plates 45, 46 and 47, the plate 45 is depressed in the region of the plate 47 and tapered upwardly toward the region of the plate 46 so that both sides of the upper surface of the device contact the plane of the lower surface of the pallet platform.

It should be noted that the spring biased plates 46 and 47 provide a braking action for the pallet as they bear against the inner side Walls of the pallet runners and this is in addition to the braking action provided by the entire guide plate 45 pressing upwardly against the bottom surface of the pallet platform.

Although only certain embodiments of the invention have been shown and described it should be understood that the invention can be manufactured in many different ways without departing from the true scope of the invention as defined by the appended claims.

I claim:

1. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners, comprising, a strapping station, a strap guide plate at said strapping station, and bias means for urging said strap guide plate upwardly against the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening.

2. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners, comprising, a strapping station, a strap guide plate at said strapping station, bias means for urging said strap guide plate upwardly against the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening, and stop means for ordinarily limiting the height of the strap guide plate when a pallet is not positioned at the strapping station.

3. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform, comprising, a strapping station, a strap guide plate at said strapping station, bias means for urging said strap guide plate upwardly, stop means for ordinarily limiting the height of the strap guide plate when a pallet is not positioned at the strapping station to a height higher than the level of the bottom surface of the platform of the pallet, a cam surface on the end of the strap guide plate against which the pallet can be cammed to cause the strap guide plate to be lowered against the force of said bias means and allow the pallet to be moved into position over the strap guide plate.

4. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform, comprising, a conveyor, a strapping station on said conveyor, said conveyor being sloped downwardly toward said strapping station so that a pallet positioned on said conveyor is urged by gravity down the conveyor toward the strapping station, a strap guide plate mounted for vertical movement at said strapping station with its upper surface ordinarily projecting above the level of the path of the lower surface of the supporting platform of a pallet moved along said conveyor, said strap guide plate having a cam surface against which the pallet cams to cause the strap guide plate to be lowered as a pallet is moved over it along the conveyor, bias means for urging the strap guide plate upwardly so that it presses against the bottom surface of the supporting platform of the pallet moved over it and thereby provides a braking action against the pallet to arrest the gravitational movement of the pallet down the incline of the conveyor.

5. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform, comprising, a conveyor, a strapping station on said conveyor, a strap guide plate mounted for limited vertical movement at said strapping station with its upper surface ordinarily projecting above the level of the path of the lower surface of the supporting platform of a pallet moved along said conveyor, said strap guide plate having a cam surface against which the pallet cams to cause the strap guide plate to be lowered as a pallet is moved over it along the conveyor, bias means for urging the strap guide plate upwardly so that it presses against the bottom surface of the supporting platform of the pallet moved over it and thereby provides a braking action against the pallet to arrest movement of the pallet along the conveyor.

6. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners, comprising, a conveyor, a strapping station on said conveyor, a strap guide plate mounted for limited vertical movement at said strapping station with its upper surface ordinarily projecting above the level of the path of the lower surface of the supporting platform of a pallet moved along said conveyor, said strap guide plate having a cam surface against which the pallet cams to cause the strap guide plate to be lowered as a pallet is moved over it along the conveyor, bias means for urging the strap guide plate upwardly so that it presses against the bottom surface of the supporting platform of the pallet moved over it to bridge across said open bottom strap opening and also thereby provide a braking action against the pallet to arrest movement of the pallet along the conveyor.

7. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners, comprising, a strapping station, and a strap guide at said strapping station positioned to contact the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening, said strap guide being laterally adjustable so as to fit between differently spaced pallet runners, the adjustability of said strap guide being obtained by having it divided into two or more overlapped sections which are movable on each other.

8. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending trans versely of the support runners, comprising a strapping station, and a strap guide at said strapping station positioned to contact the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening, said strap guide being laterally adjustable so as to fit between differently spaced pallet runners, the adjustability of said strap guide being obtained by having it divided into two or more overlapped sections which are movable on each other, said overlapped sections being ordinarily biased by bias means to provide the guide with its greatest width, said overlapped sections having camming surfaces against which the inside walls of the runners of a pallet can cam to automatically adjust the width of the strap guide to the inside width of the space between the runners as the pallet is moved over the strap guide.

9. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners, comprising, a conveyor, a strapping station on said conveyor, a strap guide plate mounted for limited vertical movement at said strapping station with its upper surface ordinarily projecting above the level of the path of, the lower surface of the supporting platform of a pallet moved along said conveyor, said strap guide plate having a cam surface against which the pallet cams to cause the strap guide plate to be lowered as a pallet is moved over it along the conveyor, bias means for urging the strap guide plate upwardly so that it presses against the bottom surface of the supporting platform of the pallet moved over it to bridge across said open bottom strap opening and also thereby provide a braking action against the pallet to arrest movement of the pallet along the conveyor, said strap guide plate being laterally adjustable so as to fit between differently spaced pallet runners, the adjustability of said strap guide plate being obtained by having it divided into two or more overlapped sections which are movable on each other, said overlapped sections being ordinarily biased by bias means to provide the strap guide plate with its greatest width, said overlapped sections having camming surfaces against which the inside walls of the runners of a [pallet can cam to automatically adjust the width of the strap guide plate to the inside width of the space between the runners as the pallet is moved over the strap guide plate.

10. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners comprising, a strapping station, and a strap guide plate at said strapping station positioned to contact the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening, said strap guide plate being supported on a compression spring housed in two telescoping tubes, one of said tubes being connected to the strap guide plate and the second being in contact with the base of the strapping station.

ll. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform which is provided with an open bottom strap opening extending transversely of the support runners comprising, a strapping station, and a strap guide plate at said strapping station positioned to contact the bottom surface of a pallet positioned at said strapping station to bridge across said open bottom strap opening, said strap guide plate being supported on a compression spring housed in two vertically positioned telescoping tubes, one of said tubes being connected to the strap guide plate and the second being in contact with the base of the strapping station, one of said tubes having a laterally projecting pin engaging a longitudinal groove in the other tube, the pin and groove allowing for vertical movement of the strap guide plate by an amount equal to the length of the groove whose ends act as stops for said pin.

12. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform, comprising, a strapping station, and a strap guide at said strapping station positioned to contact the bottom surface of a pallet positioned at said strapping station, said strap guide being adjustable in width so as to fit between differently spaced pallet runners, the adjustability of said strap guide being obtained by having it divided into two or more overlapped sections which are movable on each other.

13. The combination in strapping apparatus for strapping a pallet of a type having spaced apart support runners below a load supporting platform, comprising, a strapping station, and a strap guide at said strapping station positioned to contact the bottom surface of a. allet positioned at said strapping station, said strap guide being adjustable in width so as to fit between differently spaced pallet runners, the adjustability of said strap guide being obtained by having it divided into two or more overlapped sections which are movable on each other, said overlapped sections being ordinarily biased by bias means to provide the guide with its greatest width, said overlapped sections having camming surfaces against which the inside walls of the pallet nunners can cam to automatically adjust the width of the strap guide to the inside width of the space between the runners and provide braking of the pallet as the pallet is moved over the strap guide.

References Cited in the file of this patent UNITED STATES PATENTS 2,632,381 Buckland Mar. 24, 1953 

